Spatial working memory performance in children and adolescents with major depressive disorder and dysthymic disorder

Spatial working memory (SWM) is known to be impaired in children with Major depressive disorder (MDD), and, separately, Dysthymic disorder (DD) (DSM V persistent depressive disorder equivalent). Yet, it remains unclear whether MDD or DD is associated with worse SWM impairment, whether DD adds to the SWM impairments evident in MDD and whether these findings are evident in children as well as adolescents with MDD and DD.

The association of SWM and its strategy and spatial span components is explored in carefully defined children and adolescents (age 6-16 years) with MDD alone (N = 29), MDD and DD (N = 130), DD alone (N = 154) compared to healthy typically developing participants (N = 107), controlling for age, gender, full scale IQ and social adversity status. The relationship between SWM and its strategy and span components and anxious/depressed and inattentive symptoms were also examined.

MDD was associated with worse SWM impairment than DD and there was no evidence of an additive effect of MDD and DD on SWM, strategy and spatial span deficits. Further, these findings were age-independent.

The data presented are cross sectional and limited to SWM deficits in MDD and/or DD.

This study concurs with and extends current influential models about the cognitive effects of MDD and DD. Clinical implications and future research directions are discussed.